title: In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites.
abstract: OBJECTIVE
  To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL) and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL) used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI) and enamel condition in scanning electron microscopy (SEM).
  
  
  METHODS
  Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed.
  
  
  RESULTS
  Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM) analysis revealed the debonding spots and the enamel surface integrity.
  
  
  CONCLUSIONS
  Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.
authors.forename: Murilo Gaby
authors.initials: MG
authors.lastname: Neves
authors.forename: Gustavo Antônio Martins
authors.initials: GA
authors.lastname: Brandão
authors.forename: Haroldo Amorim
authors.initials: HA
authors.lastname: de Almeida
authors.forename: Ana Maria Martins
authors.initials: AM
authors.lastname: Brandão
authors.forename: Dário Ribeiro
authors.initials: DR
authors.lastname: de Azevedo
mesh_terms: D000269:Adhesives / Q000032:analysis; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003743:Dental Enamel; D003799:Dental Stress Analysis; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D058105:Polymerization; D019279:Resin Cements; D055116:Self-Curing of Dental Resins; D033081:Shear Strength; D018709:Statistics, Nonparametric
chemical_list: D000269:Adhesives; D003188:Composite Resins; D019279:Resin Cements; C477790:Transbond XT; C588078:alpha plast; C588079:natural ortho; D017438:Bisphenol A-Glycidyl Methacrylate
keywords: Composite resins; Scanning electron microscopy; Shear strength